Needle cooling device for sewing machines



April 15, 1952 LJJ. scHw m-z 2,593,203

NEEDLE COOLING DEVICE FOR SEWING MACHINES Filed Oct. 19. 1949 lllllllllllllllll Louis J. Schwartz B) waoi im WWW 3/402 Patented Apr. 15, 1952 2,593,203

UNITED STATES PATENT OFFICE NEEDLE COOLING DEVICE FOR SEWING MACHINES Louis J. Schwartz, Slatington, Pa., assignor to Ignatius Billcra and Anthony Billera, both of Allentown, Pa.

Application October 19, 1949, Serial No. 122,165

4 Claims. (Cl. 112218) My invention relates to improvements in needle cooling devices for sewing machines.

By way of premise, needles of sawing machines, 'under high speed and prolonged operation, become hot as a result of friction and bend so as to become useless, or cut the thread by heat, or break with consequent danger to operators from flying needle fragments.

Having the foregoing in mind, the primary ob ject of my invention is to provide a practical efficientj device for maintaining such needles cool, while'gperating, whereby to obviate the disadvantages above set forth as resulting from hot needles, and to attain greater eificiency and economy in operation of such machines.

Another object is to provide a device for accomplishing the above which is of simple construction and few parts so as to reduce the cost of manufacture, and which is easy to install in present day sewing machines, without altering the basic structure of the machine.

Other and subordinate objects, within the purview of my invention, together with the precise nature of my improvements will be readily understood when the succeeding description and claims are read with reference to the drawing accompanying and forming part of this specification.

In said drawing:

Figure l is a view in vertical section, partly in side elevation, illustrating my improved needle cooling device with. the needle bar in substantially its downward limit of movement;

Figure 2 is a view in side elevation of the device, partly broken away and shown in section, and with the needle bar in substantially its upward limit of movement;

Figure 3 is a view in horizontal section taken on the line 3-3 of Figure 1 and drawn to a larger scale Figure 4 is a view in vertical section taken on the line 4-4 of Figure 3 and drawn to a still larger scale.

Referring to the drawing by numerals, according to my invention, as illustrated, a hollow, preferably tubular, needle bar I is provided and slidably fitted in a vertical similarly shaped guide sleeve 2 fixed, in a manner presently described, in upright position and depending below the usual overhanging head arm 3 of a conventional sewing machine. The needle bar extends out of the lower end of the guide sleeve 2 and is verticallyreciprocable therein into lower and upper limits of movement shown in Figures 1 and 2 respectively. The lower end 4 of the needle bar 2 I is solid and closed with the exception of a pair of diametrically opposite air discharge bores 5 converging relatively downwardly toward the vertical axis of said bar and the purpose of which will presently be seen. A suitable coupling member 6 on the needle bar I is provided for coupling said bar to the usual rocker arm, not shown, of the sewing machine for reciprocation of said bar I by said rocker arm in the usual manner.

Theguide sleeve 2 is preferably fitted in a vertical bore 1 of the head arm 3 and may be fixed therein in any suitable manner, as by a set screw 8. Vertical air inlet slots 9 in the guide sleeves 2 spaced circumferentially around the same between said arm and the lower end of said sleeve are provided for maintaining the sleeve 2 cool in a manner presently apparent.

A plunger I0 is slidably fitted in the needle bar I and relative to which said bar I reciprocates, said plunger being fixed on the lower end of a plunger carrying rod I I extending downwardly' through the guide sleeve 2 partway into said bar. The plunger carrying rod II is suitably fixed at its upper end to a screw plug I2 threaded into the upper end of the guide sleeve 2 with said rod in the axis thereof.

Means are provided for detachably securing a needle I3 in the lower end 4 of the needle bar I and will now be described.

An axial needle socket I4 is provided in the lower end 4 of said needle bar I. A needle clamping plug I5 preferably rectangular, extends trasversely into the lower end 4 of the needle bar I, from one side of said bar, and is slidably fitted in a correspondingly shaped plug socket I6 formed in said end 4. The clamping plug I5 bisects the needle socket I4 and is provided with a vertical needle clamping bore I! through which the needle I3 extends and which is arranged at a slight angle to the needle socket M. A reduced threaded shank IS on one end of said plug I4 is slidably fitted in and extends out of a bore I9 extending from the plug socket I 6 to the side of said end 4 opposite that first mentioned. A knurled nut 20 on the shank I8 is rotatable against said end 4 of the needle bar I to slide said plug laterally of said needle I3 in one direction and bind the same in the needle socket I4 and bore I! to clamp said needle in place. The needle clamping bore I'l being at the described angle to the needle socket I4 serves to bind the upper end of said needle I3 and thereby facilitate clamping the needle I3 in place. By loosening the nut 20 the needle clamping plug I5 may be slid endwise in one direction to posi- .tion the needle clamping bore l'l relative to the needle socket M to free the needle [3 for removal and replacement. A leaf spring 21 on the first mentioned side of the needle bar I and bearing against the needle clamping plug I5 urges said plug toward clamping position to prevent the needle is from dropping out of the needle bar i before it can be grasped for removal.

The operation of the described needle cooling device will be readily understood. The plunger id, in the downward limit of movement of the needle bar I is spaced above the lower end 4 of said bar. As the needle bar rises, said plunger forces air out of the lower end portion of said bar through the air discharge bores 5 to impinge against the needle 13 and maintain the same cool. As the needle bar i descends into its lower limit of movement, air is drawn into the lower end portion of said bar for discharge out of the air discharge bores 5. The air inlet slots 9 admit air into the guide sleeves 2 above the needle bar I to maintain said bar and sleeve cool. As will of course be understood, the needle 13 operates on the work 22 in conjunction with the usual presser foot 23 in the usual manner.

The foregoing will, it is believed, sufiice to. impart a clear understanding of my invention, with out further explanation.

Manifestly, the invention, as described, is susceptible of modification, without departing from the inventive'concept, and right is herein reserved to such modifications as fall within the scope of the appended claims.

Having described my invention, what is claimed as new is:

1. In a sewing machine, a vertical hollow needle bar having a lower needle carrying end, a needle, means to mount the needle in said lower end of said bar, a fixed vertical guide sleeve in which said bar is fitted to depend out of the same and be reciprocated vertically therein, a plunger in said bar, means for fixedly attaching said plunger to said sleeve to cause air pressure in said bar below the plunger upon upward movement of said bar, and means in the lower end of said bar for discharging the air under pressure below said plunger downwardly against said needle to maintain the same cool. i r

2. In a sewing machine, a vertical hollow needle bar having a lower needle carrying end, a needle, means to mount the needle in said lower end of said bar, a fixed vertical guide sleeve in which said bar is fitted to depend out of the same and be reciprccated vertically therein, a plunger in said bar, means for fixedly attaching said plunger to said sleeve and holding said plunger stationary relative to said bar whereby upon upward movement of said bar relative to said plunger air pressure will be effected in said bar below said plunger, and means in the lower end of said bar for discharging the air under pressure below said plunger downwardly against said needle to maintain the same cool, the first mentioned means comprising an axial needle socket in said end of said bar, the last mentioned means comprising air discharge ports converging relatively downwardly toward said needle.

3. In a sewing machine, a vertical hollow needle bar having a lower needle carrying end, a needle, means to mount the needle in said lower end of said bar, a fixed'vertical guide sleeve in which said bar is fitted to depend out of the same and be reciprocated vertically therein, a plunger in said bar, means for fixedly attaching said plunger to said sleeve and holding said plunger stationary relative to the bar whereby upon upward move ment of saidbarrelative to said plunger airpressure will be effected in. said bar below said plunger, and. means in, the lower end of said bar for discharging the air under pressure below said plunger downwardly against said needle tomain tain the same-cool, the second mentioned means comprising a screw plug in the upper end of said sleeve; and a rod depending from'said plug with the plunger fixed thereto.

4. In a sewing machine, a vertical hollow needle bar having a lower needle carrying end, a needle mounted in said end of said bar, means to mount said needle bar for vertical reciprocation including a vertical fixed guide sleeve for said bar, and means to force air out of said lower end of the needle bar against said needle to cool the same uponupward movement of said needle bar relative to said sleeve comprising a relatively station ary plunger in said needle bar having one end fixed in the upper end of said sleeve.

LOUIS J. SCHWARTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Runcie Apr. s, 1948 

